The U.S. Capitol Police on Sunday said an officer from Magnolia died of a heart attack after shoveling snow at his Delaware home on Saturday.

Vernon J. Alston Jr., 44, was an officer for 20 years, said Tasha Jamerson, a spokeswoman with the agency.

“The death of Officer Alston is truly a tragic loss for the Alston family and the United States Capitol Police, which in fact is one in the same,” said Chief of Police Kim Dine, in a statement. “Officer Alston was someone who loved his job, and his loss leaves a huge void in the hearts of all of the men and women at the USCP.”

Senate Minority Leader Harry Reid announced Alston's death on Sunday, calling him "a fixture on the Capitol grounds."

"I am always grateful for the dedication and sacrifice of the Capitol Police force, and Officer Alston was an example of that," he said.

Efforts to reach Alston's family were unsuccessful.

His wife, Nicole Alston, told the Associated Press that he had been helping clear his driveway and helping neighbors when he collapsed Saturday afternoon.

"I was about 2 feet away from him," she said. "He screamed my name. He collapsed, and he was gone."

An ambulance had to be towed in order to reach the family, but Alston said she didn't think it would have been possible to save her husband's life no matter how quickly aid arrived.

Her husband, a stylish dresser with a passion for contemporary furniture, "was a real people person. He was a very loving man," she said. "People looked to him for advice. He always tried to make people laugh. He was just a really genuine and good man. People loved him. I've received so many calls."

The couple had been married for seven years and had a 3-year-old son. He had a teenage son and daughter from a previous marriage and his wife's teenage daughter from a previous marriage.

Heart attacks caused by shoveling are rare, said Dr. George Moutsatsos, a New Castle County based cardiologist and president of Delaware’s branch of the American College of Cardiology.

"Most of the time the people who it affects are people who have documented coronary disease or individuals who have silent, undiagnosed coronary disease," Moutsatsos said. "There are so many of us who have underlying coronary disease that not have been documented."

Shoveling snow can act like a "perfect storm." It is a very dramatic and acute exercise to begin with, Moutsatsos said, and the cold weather constricts the coronary arteries and raises blood pressure, which makes it difficult for the heart to pump blood.

"People never warm up when they shovel snow," he said. "So you are going in 110 percent early on against adverse conditions as opposed to getting on a treadmill and going slowing or playing tennis and warming up."

When shoveling, he said, try and take breaks and start with small scoops of snow.

"You should warm up, but because it's not an exercise people are not trained in their mind to warm up," Moutsatos said.

Jen Rini can be reached at (302) 324-2386 or jrini@delawareonline.com. Follow @JenRini on Twitter.